Combination impression tray and matrix clamp



Dec. 23, 1952 H. STONE COMBINATION IMPREssIoN TRAY AND MATRIX CLAMP Filed Sept. 14, 1951 INVENTOR [Ea/x4400 ,5. 57-0 /v m Um/20km 772 mazqflmz ATTORNEYS Patented Dec. 23, 1952 COMBINATION IM'PRESSION TRAY AND MATRIX CLAMP Leonard H. Stone, Lakeport, Calif.

Application September 14, 1951, Serial No. 246,543

' 4 Claims.

This invention relates to dental impression trays, and more particularly to an improved combination impression tray and matrix clamp adapted to be filled with plastic material for the purpose of taking a mold or impression of a patient teeth.

A main object of the invention is to provide a novel and improved combination dental impression tray and matrix clamp which is simpl in construction, which is easy to manipulate, and which enables a dentist to efliciently restore badly broken down or decayed teeth using the newly developed acrylic restoratives or silicates, or similar material.

A further object of the invention is to provide an improved combination dental impression tray and matrix clamp which is inexpensive to construct, which is durable, which enables the dentist to obtain a split impression of the tooth to be restored and then to return the matrix to the exact position on the tooth after inserting the soft plastic or acrylic material into the tooth, the improved device enabling the dentist to bring the segments of the matrix into proper positions and to put clamping pressure on the soft material and hold said material immobile until cured.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a diagrammatic front elevational view of a row of patients teeth showing one of the teeth in a decayed or partially broken away condition whereby restoration of the tooth is desirable.

Figure 2 is a side elevational view showing the manner in which the impression tray of the present invention is employed to obtain an impression of the patients teeth.

Figure 3 is a vertical cross sectional view taken through the combination matrix tray of the present invention after the impression has been made and the segments of the tray have been spread apart.

Figure 4 is a perspective view of the impression tray and matrix of the present invention after the patients dental impression has been made.

Figure 5 is a top plan view of the improved combination impression tray and matrix device of the present invention.

Figure 6 is a perspective view of the structure 01 Figure 4 shown with the segments spread apart and the clamping ring rotated to a disengaged position with respect to said segments.

Figure '7 is a diagrammatic front elevational view, similar'to Figure 1, showing the appearance of the patients teeth after the restoration of the broken tooth has been completed.

Referring to the drawings, the combination'impression tray and matrix is designated generally at H and comprises a pair of tray elements l2 and I3 hinged together by a, transverse hinge l4 connecting the edges of the tray elements [2 and I3, said tray elements being arranged to define a generally rectangular, box-like structure when the tray elements are arranged in the manner shown in Figure 4. The tray element l2 has the side walls l5 and I6 and the end wall I1, and the tray element l3 has the side walls l8 and I9 and the end wall 20. The top edges of the side walls of the respective tray elements l2 and I3 are inclined downwardly toward the transverse hinge M to provide lateral clearance for the insertion of the tray into a patients mouth, for example in the manner illustrated in Figure 2, the inclined top edges being shown at 2| and 22.

Designated at 23 i a rectangular ring hinged at 24 to the end wall 20 of tray element l3, the ring 23 being arranged to embrace both tray elements in the manner shown in Figure 4. The forward portion of the ring 23 includes a block member 25 engageable with the end wall ll of tray element l2, and threaded through the block member 25 is a clamping screw 26 which is clampingly engageable with the end wall I! of tray element l2 to rigidly lock the elements l2 and I3 in fixed positions within the ring member 23. The sides of the ring member 23 are bowed downwardly at 28, as viewed in Figure 4, to provide lateral clearance above the inclined top edges 2!, 22 of the side walls of the tray.

As shown in Figure 1, a patient may hav a partially decayed or broken tooth 29 which it is desired to restore. In restoring the tooth, the tooth 29 is first built up to its normal contour with any suitable material, such as inlay wax, gutta-percha, or modeling compound. An

impression is then taken with plaster of Paris or similar material in the tray, arranged as shown in Figure 2, the tray being in closed position and the clamping screw 26 being tightly engaged with the end wall I! of the tray element l2. Figure 2 illustrates the position of the matrix tray II when this impression is being made.

After the impression has been made the screw 26 is loosened, the ring 23 is disengaged from the tray elements, and the plaster impression is split in half and is removed from the patients mouth, as shown in Figure 3. The tray is then set aside for subsequent use. The material used to build up the contour of the broken tooth 29 is then removed and a suitable cavity is prepared in the tooth for the retention of the permanent restoration compound such as acrylic material or the like. The tray is then opened, as shown in Figure 6, and the dental impressions of the cast segment, shown at 30, contained in the tray segment 13 are then fitted against the lingual or inner surfaces of the teeth in the same position as when the impression was made, the ring 23 being in a disengaged position with respect to the other tray segment 12. The cavity in the tooth to be restored is then filled with the prepared acrylic or other suitable material, with a slight excess of material. As soon as the filling material is well packed into the cavity, with a slight excess thereof, the remaining portion of the original cast is brought up into a position engaging the teeth similar to that in which the impression was taken by swinging the tray segment, l2 to the position of Figure 4 relative to the tray element IS, the ring 23 is engaged with the tray element 12 with the block element 25 abutting the Wall ll of tray element 12, and the screw 2'6 is tightened, forcing the acrylic material into all portions of the cavity in every direction. The tray is then left in position in the mouth for the length of time necessary for the curing of the acrylic or other material employed, as directed by the manufacturer of the material, usually for a period in the neighborhood of twenty minutes. At the end of this time, the screw 26 is loosened and the ring 23 is dropped into releasing position, allowing the tray to be removed in the manner shown in Figure 3. This operation provides a well condensed filling, with a slight excess of material on the restored tooth, which is removed with the usual discs or grinding wheels and finally polished with acrylic polish on felt Wheels.

The above operation provides a properly condensed plastic filling,'the materialbeing forced into the cavity and into all undercuts therein in all directions, the matrix forcing the plastic material into a dense mass of the proper shape, whereby accurate restoration of badly decayed or broken down teeth may be readily performed. The acrylic fillings may be suitably tinted or colored to match the tooth color, providing a natural restoration, and the entire operation may be performed by the dentist in his own office without requiring the assistance of outside laboratories.

While a specific embodiment of an improved combination dental impression tray and matrix 4 clamp has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. A combination dental impression tray and matrix clamp comprising a pair of tray elements adapted to receive plastic material for making a dental impression, means hingedly connecting said tray elements on a transverse axis, a ring member arranged to receive said tray elements, and a clamping screw threadedly engaged through said ring member and arranged to engage one of the tray elements.

2'. A combination dental impression tray and matrix clamp comprising a pair of tray elements adapted to receive plastic material for making a dental impression, means hingedly connecting said tray elements on a transverse axis, a-ring member arranged to receive said tray elements, and clamping means carried by said ring member and arranged to engage one of the tray elements. Y

3. A combination dental impression tray and matrix clamp comprising a pair of tray elements adapted to receive plastic material for making a dental impression, means hingedly connecting said tray elements on a transverse axis, a ring member hinged to the outer portion of one of the tray elements and arranged to receive said tray elements, and clamping means carried by said ring member and arranged to engage the other tray element. I

4. A combination dental impression tray and matrix clamp comprising a pair of tray elements adapted to receive plastic material for making a dental impression, means hingedly connecting said tray elements on a transverse axis, a ring member hinged to the outer portion of one of the tray elements and arranged to receive said tray elements, and a clamping screw threadedly engaged through said ring member'and arranged to engage the other tray element, the top edges of the side walls of the tray elements being inclined downwardly toward the transverse hinge axis of the tray elements and the sides of the ring member adjacent said edges of the side walls being bowed downwardly to provide lateral clearance above the inclined top edges of said side walls.

LEONARD H. STONE No references cited. 

